Electric-fuse tester.



J. H. GARY.

ELECTRIC FUSE TESTER.

APPLICATION IILBD JUNE 18, 1909.

968,448. Patented Aug.23, 1910.

JAMES H. CARY, OF PORTLAND, MAINE.

' ELECTRIC-FUSE TESTER.

Specification of Letters Patent.

Patented Au 23, 1910.

Application filed June 18, 1909. SeriaLNo'." 502,888.

To all whom it may concern:

Be it known that I, JAMES H. CARY, a citizen of the United States of America, and

a resident of Portland, in the county of Cumberland, State of Maine, have invented certain new and useful Improvements in Electric-Fuse Testers, of which the following is a specification.

My invention relates to an apparatus for testing electric fuses. These fuses as now manufactured are of two general varieties, the plug fuse and the cartridge fuse, the former having an end terminal at the end of the plug, a side terminal consisting of the metal sheath which is usually screw threaded to screw into the socket and the latter having metal cylindrical ends constituting the cont-acts. These fuses as they are placed on the market are often defective and many times such defective fuses are placed in posit-ion in a light or power circuit and in absence of a convenient testing device much delay and often expense are incurred.

Hitherto it has been customary, among users or workmen, to test fuses by touching their terminals to the terminal wires of a magneto allowing the current to. pass through the hand or by connecting them in a bell or light circuit, the ringing of the bell or the glowing of the light indicating the passage of the current through the fuse. uch means of testing fuses were not convenient or portable and the object of my invention is to provide a portable fuse tester constructed in convenient and compact form which may be used by dealers, electricians, repairers and others so that all fuses before being sold or used may be quickly and easily tested. This object I accomplish by means of the invention hereinafter described and claimed which consists essentially of a containing box or casing having therein a battery or other form of generator and a hell or other signaling device both of them in circuit with a pair of electrodes fixed to the box in convenient position to be contacted by the terminals of the fuse. The bridging of the space between the electrodes by the fuse completes the circuit and rings the bell .if. the fuse is perfect.

I illustrate my invention by means of the accompanying drawing inwhich is shown one form of my invention adapted to be used on store counters and like places.

In the drawing, Figure 1 is a side view of my device with one sideremoved to show the contents, Fig. 2 is a plan, Fig. 3 is an end View with the end of the box removed, Fig. 41s adiagram showing the wiring system and Fig. is ,a detail of an alternative form of electrode.

, In the form of my invention shown above, A represents a box or casing of suitable size and form, preferably of such a size that it may be'easily transported. In the box are located'a generator of electricity and a suitable si'gnaling device. As herein shown, the interior of'the box is divided into two co1npartments by means of a partition a and in one compartment is shown a dry cell battery element G and in the other an electric bell F In place of the battery, I may make use of any other means for generating a current as, for instance, a small magneto and in place of the bell any suitable signaling device as a buzzer or light or any device serving to indicate the closing of the circuit. The battery and bell are included in an open circuit with a pair of electrodes secured to the box and adapted to contact with the ends of'a' fuse to be tested. These electrodes may be of any suitable form to connect the terminals of the fuse but it is desirable that electrodes should be provided to test both the cartridge and the plug fuses. As here shown I provide two separate pairs of electrodes for testing the two different forms of fuse although as hereinafter shown a single pair may be made to answer for both.

As .here shown, the cartridge fuses are tested by the electrodes B each of which is composed of a pair of elongated side pieces set at an angle with each other and forming .a channel or angular space in which the ends of the fuse S rest. The electrodes B are pivoted in line with each other to supports 6- which are secured to the top of the box. The side pieces of the electrodes B as here shown are separated at their outer ends and for this purpose they are set at a small angle horizontally so that the size of the- V-shaped recess increases toward the end to accommo date the larger and longer fuses. By tilting the electrodes up so that they incl ne slightly toward each other contacts are msured at the extreme ends of the fuse. The electrodes B are made long enough to take the largest fuses on the market and they are close enough together to be bridged by the shortest fuses.

Electrodes are provided for testing the tridge fuses.

plug fuses and in these electrodes a base plate is used tocontact with the end terniinal and a side plate adjacent to and extending above the base late for contacting with the side terminal 0 the plug. As here shown, I provide a base plate D secured to the box and a side plate C which is in two parts set at an angle with each other and connected together at the base so as to form a recess with angular sides to insure a bearing at two points on the side terminal of the plug fuse. In Fig. 3 I show a plug fuse P in position in contact with the electrodes.

In Fig. 4 is shown the system of wiring by Y which it will be seen that one side of the battery circuit includes the bell and one of the electrodes of each pair and the other side of the circuit includes the two other electrodes. Then the space between either of the pairs of electrodes is bridged the circuit is closed and the bell rung. I

In Fig. 5 I show a pair of electrodes adapted to test both plug fuses and ear- 0 is an elongated base plate and 0' is a vertical plate extending above the level of the base plate 0. In testing the plug fuse the end is placed on the base plate and the side held against the plate 0. In testing the cartridge fuse one end is rested on the plate 0 and the other on the base plate 0.

I desire it to be understood that I do not limit inyselfto the details of construction ooaaas above shown but the invention may be constructed in a great variety of forms while keeping within the scope of the invention.

It will be seen that with this device both plug and cartridge fuses of any size may be readily tested, the device may be easily transported or may be permanentlylocated on a shelf or counter or secured to a wall.

Testing devices of this same general form may be made of suitable size and shape to carry in the pocket if desired so that it'may be even more convenient'than the form here shown.

I claim 2- 1. The herein described apparatus for testing electric fuses including a pair of electrodes set in line and each composed of two side pieces set at an angle to form a channel and adapted to contact each end of a cartridge fuse.

2. The herein described apparatus for testing electric fuses including a pair of electrodes set in line and pivoted at their adjacent ends, each composed of a pair of side pieces set at an angle to form a channel to contact each end of a cartridge fuse.

In witness whereof I have hereunto set my 0 hand this 10th day of June, 1909.

JAMES H. CARY.

Witnesses:

S. W. BATES, ELEANOR W. DENNIS. 

